Process for obtaining alumina and phosphates



UNITED stars rRI'rznorEE-ANn HANS ,BRENEK, ome a-41a, snamnnm nssrenons TO THE FIRM:-

RHENANIAeK'UNHEIM vnnnnv oirn vzrscnznn FABBIKEN} axrrnnensnnrsonaimi Patented June 16, 193-1 BERLIN, GERMANY v lrnoonss r01; onmnrivmennunmaynlvn PHOSfI-IATES o a No nm n Application filed m y as, 1927 se ial No. 2 07,809, and tea -an Ju1y30,.1926.

invention has,v reference to the proc-pess for obtainingalumina and phosphates,

Whichmay be used as fertilizers,from alumt,

num phosphates, which consists in subjecting alumina phosphates mixed withalkaline. earth metal oxides and alkaline metal oxides to a'heating. V 1

The invention comprises an improvement of this process which consists incarrying out the reaction above referred to in the presence of steam. It has been found that hereby the reaction will be considerablyfavoured and that it is possible to makeuse of salts, which" are more difticult to be decomposed than the carbonates, as alkali; and alkaline earth metal compounds, if the reaction takes place in the presence of steam; Thus it is possible to uti-. lize, the cheaper alkali metal sulphates and alkaline earth metal sulphates either alone 'orin mixturewith the carbonates, other salts or the oxides of the alkali metal and alkaline earth metal. Due to the action of the steam uponthe mixture a complete decomposition .ofthe sulphates can be obtained; Hereby S0 is'freed and escapes. It may be utilized as sulphurous acid, Alsoflthe chlorides are used withadvantage. In thiscase H61 is ob tained as 'by-product, which maybe utilized current of steam. From the calcined product, I

in 100'pa-rts of which there were 23 parts ,Al U 22.5'parts were dissolved out in the 7 as hydrochloric acid. The process is carried out at sinteringtemperatures ,for the mix-1 supply is. rendered unnecessary. Examples of such fuels are water-gas, oil gas, lignite producer gas or the like.

The most favourable result will be obtained if the proportions inthe crude mixture con- 'taining alumina phosphate, alkaline earth cule alkali metal oxide and for 1 molecule I i In this manner alkali dicalf ciumphosphate is obtained, if calciumoxide islused 'as alkaline earth compounds. In 5 cases where the material to be treated contains silica, there must be added such" a further quantity of alkaline earth metal oxide, that" alkaline earth metal orthosilicate (213.0.Si0g) can be formed.

a An example illustrating the mode in which the lnvention can be carried into practiceis. j

as follows-:- I

parts ofa South African aluminum phosphate having the following composition 22.8% of H 0; 34.7% of P 0 32.4% of A1 0 4.8% or F6203; 2.5% of S10 3.2% of @210 (not combined with phosphoric acid) were'mixed in powderedstate with 66 parts I of anhydrous gypsum corresponding to 2.

molecules of referred to P 9 36 parts of iNa SO corresponding to ;1 molecule of 'Na O referred ,to'P2O and an additional 4 5 parts of Na SO correspondingto 1 molecule of Na G referred to A1 0 and 3.66 parts of gypsum to bind the silica as orthosilicate This mixture was calcined at a temperature of about 1200 C. forfrom l to 2 hours in a form of sodiuinaluminate treatment with water, thus affording a yield of about 98%.

The phosphoric acid in the residue was practicall coin letel citrate-soluble.

y P y onlyone of the sulphates be replaced by a chloride.

- What e claiinand desire to secure by Let ter's Patent of the United States is V T c 11 'A' processgfor obtaining alumina and phosphates ,whichlmay'be used fertilizers, from ,aluminum:phosphate comprising suhejecting a mimure .of aluminium phosphates a1rd-a1ka1i11e earth*metalj comphunds and alkali metal compounds to a heating at sinteri'ng' temperatures for said mixture 1n the presence of steam- 2. A process for obtaining alumina and prosphates which may be used as fertilizers, from aluminum phosphate comprising sub jecting a mixture of aluminium phosphates and alkaline earth metal sulphates and alkali metal sulphates to a heating at sintering temperatures for said mixture in the presence of steam.

3. A process for obtaining alumina and phosphates which may be used as fertilizers,

from aluminium phosphate comprising sub-' jecting a mixture of aluminium phosphates; alkaline earth metal sulphates,other alkaline earth metal salts, alkali metal sulphates and other alkali metal salts to a heatingat sintering temperatures for said mixture in the presence of steam.

41A process for obtaining alumina and phosphates'which'may be used as fertilizers, from aluminium phosphate comprising sub: jectin a mixture of aluminium phosphates and al 'aline earth metal salts and alka i salts to a heating at sinteri ng temperatures forsaid mixture in thepresence of steam, sa d mixture containing for 1 moleculeof phosphoric acid 2 molecules of alkaline earth metal oxide and 1 molecule ofralkali metal oxide and for 1 molecule of alumina a further molecule of alkali met-a1 oxide.

k 5. A process for obtaining alumina and; phosphates which may be used as fertilizers, from aluminium phosphate comprising subjecting a mixture of aluminium phosphates and alkaline earthmetal sulphates and alkali metal sulphates to a heating at sintering temperatures for said mixture in the presence of steam, said mixture containing for 1 molecule of phosphoric acid 2 molecules of alkaline earth metal sulphate and 1 moleculeof alkali metal sulphate and for 1 molecule of alumina a further molecule of alkali metal sulphate.

6. A process for obtaining alumina and phosphates which may be used as fertilizers, from aluminium phosphate comprising subjecting a mixture of aluminium phosphates and alkaline earth 'metal' salts and alkali metal salts to a heating atsintering tempera tures for said mixture in the presence of steam, said mixture containing such quanti ties of alkaline earth metal oxide that any silica present in the mixture can be bound as alkaline earth orthosilicate.

7. A process for obtaining alumina and phosphates which may be used as fertilizers, from aluminium phosphate 'comprisingsubjectinga mixture of aluminium phosphates and alkaline earth metal sulphates and alkali metal sulphates to a heating at sintering temperatures for said mixture in the presence of i steam, said mixture containing such quantities of alkaline earth metal sulphate that from aluminium phosphate comprising subjecting a mixture of aluminium phosphates and alkaline earth metal salts and alkali jee'tin a mixture of'aluminium phpspliizgls 1 an d a (aline earth metal sulphates and a metal sulphatesfto a heating, at sint er ing tempe i t r v' eif a iix l e i f pnzse qa steam, said mixturec ontaining tor 1 molecule or phosphoric acid 2 moleculesfof alkaline earth metal sulphate and I moleculeo f alkali metal sulphate and fo 1 molecule of al a further molecule 0 alkali metal su phate:

and in addition "there to' such quantities of lka in ar ea uma ra, y i w present in the mixture canhebound alkaline earth orthosilic a te. I

p ffer O tai ng phosphates which may be use l m na nd a s liee s,

from aluminium phosphate comprising suh jec tin amixture of aluminium phpsphati'es i s a ts and al aline earth metal salts iapd alka to a heating, at sintering temperatures vfor said mixture b the of re iment-at ia such amountsol hydrogen as tovform suflicien m, t heim e n" ai fif rbnl e mixture r 111. A process for obtaining aluminaand phosphates" which may be used as fert1l zers,

from aluminium phos hate comprising subjecting a mixture of 'a uminiurn phosphates, alkaline earth'metal'sul hates, other'alkaline earthmetal salts, alkali'metal sulphates and V other alkali metal salts to a heating at sintering temperatures for said mixture'by the aid of fuelscont'aining such amounts of hydrogen as to form sufficient steam at their combus 'tion to upon themixture.

FRITZ ROTHE. r HANS ENEK.

any silica present in the mixture can be bound as alkaline earth orthosilicate. r

8. A process for obtaining alumina and I phosphates which may be used as fertilizers, 

